The Association between Subclinical Hypothyroidism and Epicardial Adipose Tissue Thickness

Erdal Belen,Aleks Degirmencioglu,Ertugrul Zencirci,Fatih Fahri Tipi,Özgür Altun,Gültekin Karakus,Ays¸en Helvacı,Aycan Esen Zencirci,Ezgi Kalaycıoglu 대한심장학회 2015 Korean Circulation Journal Vol.45 No.3

Background and Objectives: Subclinical hypothyroidism (SH) is considered to be a potential risk factor for cardiovascular disease. Epicardial adipose tissue (EAT) thickness is also closely related to cardiovascular disorders. The aim of this study was to evaluate whether SH is associated with higher EAT thickness. Subjects and Methods: Fifty-one consecutive patients with SH and 51 healthy control subjects were prospectively enrolled into this trial. Thyroid hormone levels, lipid parameters, body mass index, waist and neck circumference, and EAT thickness measured by echocardiography were recorded in all subjects. Results: Mean EAT thickness was increased in the SH group compared to the control group (6.7±1.4 mm vs. 4.7±1.2 mm, p<0.001). EAT thickness was shown to be correlated with thyroid stimulating hormone level (r=0.303, p=0.002). Multivariate logistic regression analysis revealed that EAT thickness was independently associated with SH {odds ratio (OR): 3.87, 95% confidence interval (CI): 1.92–7.78, p< 0.001; OR: 3.80, 95% CI: 2.18–6.62, p<0.001}. Conclusion: Epicardial adipose tissue thickness is increased in patients with SH compared to control subjects, and this increase in EAT thickness may be associated with the potential cardiovascular adverse effects of SH.

SMAD4 Suppresses AURKA-Induced Metastatic Phenotypes via Degradation of AURKA in a TGFβ-Independent Manner

Jia, Lina,Lee, Hun Seok,Wu, Chun Fu,Kundu, Juthika,Park, Sang Gyu,Kim, Ryong Nam,Wang, Li-Hui,Erkin, Ö,zgü,r Cem,Choi, Jong-Sun,Chae, Seoung Wan,Yang, Ho Bin,Choi, Yoon-La,Shin, Young Kee American Association for Cancer Research 2014 Molecular Cancer Research Vol.12 No.12

<P>SMAD4 has been suggested to inhibit the activity of the WNT/β-catenin signaling pathway in cancer. However, the mechanism by which SMAD4 antagonizes WNT/β-catenin signaling in cancer remains largely unknown. Aurora A kinase (AURKA), which is frequently overexpressed in cancer, increases the transcriptional activity of β-catenin/T-cell factor (TCF) complex by stabilizing β-catenin through the inhibition of GSK-3β. Here, SMAD4 modulated AURKA in a TGFβ-independent manner. Overexpression of SMAD4 significantly suppressed AURKA function, including colony formation, migration, and invasion of cell lines. In addition, SMAD4 bound to AURKA induced degradation of AURKA by the proteasome. A luciferase activity assay revealed that the transcriptional activity of the β-catenin/TCF complex was elevated by AURKA, but decreased by SMAD4 overexpression. Moreover, target gene analysis showed that SMAD4 abrogated the AURKA-mediated increase of β-catenin target genes. However, this inhibitory effect of SMAD4 was abolished by overexpression of AURKA or silencing of AURKA in SMAD4-overexpressed cells. Meanwhile, the SMAD4-mediated repression of AURKA and β-catenin was independent of TGFβ signaling because blockage of TGFβR1 or restoration of TGFβ signaling did not prevent suppression of AURKA and β-catenin signaling by SMAD4. These results indicate that the tumor-suppressive function of SMAD4 is mediated by downregulation of β-catenin transcriptional activity via AURKA degradation in a TGFβ-independent manner.</P><P><B>Implications:</B> SMAD4 interacts with AURKA and antagonizes its tumor-promoting potential, thus demonstrating a novel mechanism of tumor suppression. <I>Mol Cancer Res; 12(12); 1779–95. ©2014 AACR</I>.</P>

A Combined Generalized Regression Neural Network Wavelet Model for Monthly Streamflow Prediction

Özgür Kisi 대한토목학회 2011 KSCE Journal of Civil Engineering Vol.15 No.8

The ability of a combined model, Wavelet-Generalized Regression Neural Network (WGRNN), is investigated in the current study for the prediction of monthly streamflows. The WGRNN model is obtained by combining two methods, Discrete Wavelet Transform (DWT) and Generalized Regression Neural Network (GRNN), for one-month-ahead streamflow forecasting. The monthly flow data of two stations, the Gerdelli Station on the Canakdere River and the Isakoy Station on the Goksudere River, in the Eastern Black Sea region of Turkey are used in the study. The forecasts of the WGRNN model are tested using the Root Mean Square Error (RMSE),Variance Account For (VAF) and correlation coefficient (R) statistics and the results are compared with those of the single GRNN and Feed Forward Neural Network (FFNN). The comparison results revealed that the WGRNN performs better than the GRNN and FFNN models in monthly streamflow prediction. For the Gerdelli and Isakoy stations, it is found that the WGRNN models with RMSE = 5.31 m^3/s, VAF = 52.3%, R = 0.728 and RMSE = 3.36 m^3/s, VAF = 55.1%, R = 0.742 in the test period are superior in forecasting monthly streamflows than the best accurate GRNN models with RMSE = 6.39 m3/s, VAF = 30.1%, R = 0.553 and RMSE = 4.19 m^3/s, VAF = 30.1%, R = 0.549, respectively.

Investigation of lateral impact behavior of RC columns

Özgür Anil,R. Tuğrul Erdem,Merve Nilay Tokgöz 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.22 No.1

Reinforced concrete (RC) columns which are the main vertical structural members are exposed to several static and dynamic effects such as earthquake and wind. However, impact loading that is sudden impulsive dynamic one is the most effective loading type acting on the RC columns. Impact load is a kind of impulsive dynamic load which is ignored in the design process of RC columns like other structural members. The behavior of reinforced concrete columns under impact loading is an area of research that is still not well understood; however, work in this area continues to be motivated by a broad range of applications. Examples include reinforced concrete structures designed to resist accidental loading scenarios such as falling rock impact; vehicle or ship collisions with buildings, bridges, or offshore facilities; and structures that are used in high-threat or highhazard applications, such as military fortification structures or nuclear facilities. In this study, free weight falling test setup is developed to investigate the behavior effects on RC columns under impact loading. For this purpose, eight RC column test specimens with 1/3 scale are manufactured. While drop height and mass of the striker are constant, application point of impact loading, stirrup spacing and concrete compression strength are the experimental variables. The time-history of the impact force, the accelerations of two points and the displacement of columns were measured. The crack patterns of RC columns are also observed. In the light of experimental results, low-velocity impact behavior of RC columns were determined and interpreted. Besides, the finite element models of RC columns are generated using ABAQUS software. It is found out that proposed finite element model could be used for evaluation of dynamic responses of RC columns subjected to low-velocity impact load.

Nonlinear finite element analysis of loading transferred from column to socket base

Özgür ANIL,Burak UYAROĞLU 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.5

Since the beginning of the 90 s, depending on the growth of the industrial sector in Turkey,factory constructions have been increased. The cost of precast concrete buildings is lower than the steel ones for this reason the precast structural systems are used more. Precast concrete structural elements are mostly as strong as not to have damage in the earthquake but weakness of connections between elements causes unexpected damages of structure during earthquake. When looking at the previous researches, it can be seen that there is a lack of studies about socket type base connections although there were many experimental and analytical studies about the connections of precast structural elements. The aim of this study is to investigate the stress transfer mechanism between column and the socket base wall with finite element method. For the finite element analysis ANSYS software was used. A finite element model was created which is the simulation of experimental research executed by Canha et al. (2009) under vertical and horizontal forces. Results of experimental research and finite element analysis were compared to create a successful simulation of experimental program. After determining the acceptable parameters, models of socket bases were created. Model dimensions were chosen according to square section column sizes 400, 450, 500, 550 and 600 mm which were mostly used in industrial buildings. As a result of this study, stress distribution at center section of the socket base models were observed and it is found that stress distribution affects triangular at the half of socket bottom and top.

TÜRK SİYASİ TARİHİNDE SİYASAL İSLAMCILIK HAREKETLERİ VE GÜNÜMÜZ SİYASAL İSLAMCILIĞINDA AK PARTİ’NİN KONUMU

Özgür SARI 한국외국어대학교(글로벌캠퍼스) 중동연구소 2007 중동연구 Vol.25 No.2

The political Islam and islamist movements have being existed in the Turkish political and social life until today. Those movements are, nowadays, the most hot and argumentative topics, since Justice and Development Party (AKP), that is called an islamist party by some scholars, has taken the power in the Turkish political life. It is, at the same time, the first time that a political party called as an islamist party is in power. Islam is not a pure religion, but it is, at the same time, a life style and political ideology that dominate Turkish political history. To understand the position of AKP in those movements, the historical processes of those heterogeneous movements in the late Ottoman and Turkish history must be understood.

Design, Fabrication and Vision Based Operational Analysis of Novel Shape Memory Alloy Micro Grippers

Özgür Yurtsever,Haluk Küçük 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.9

Object grip, grasp, hold and place type of tasks incorporate specific engineering design concepts. Considering such principals, eight gripper mechanisms were designed and produced which can be classified as micro grippers due to their small workspace, precise grasping and holding abilities. Common characteristics of all the designs are that, without using any electric motor, the open–close operation is by virtue of shape-memory alloys. Each gripper is designed for different purposes with different operational principles of which four were initially open and the other four were initially closed configurations. Parametric studies were performed by changing the duty cycle and frequency of pulse width modulation using a signal generator followed by measurement of gripper jaw clearance, open–close period, average open–close velocities, gripping force, holding and lifting abilities of the designed gripper mechanisms. Jaw displacement and velocity parameters were computed by image processing of video records captured during the operation of the gripper mechanisms.

Vibration measurement and vulnerability analysis of a power plant cooling system

Özgür ANIL,Sami Oğuzhan AKBAŞ,Erkan KANTAR,A. Cem GEL 국제구조공학회 2013 Smart Structures and Systems, An International Jou Vol.11 No.2

During the service life of a structure, design complications and unexpected events may induce unforeseen vibrations. These vibrations can be generated by malfunctioning machinery or machines that are modified or placed without considering the original structural design because of a change in the intended use of the structure. Significant vibrations occurred at a natural gas plant cooling structure during its operation due to cavitation effect within the hydraulic system. This study presents findings obtained from the in-situ vibration measurements and following finite-element analyses of the cooling structure. Comments are made on the updated performance level and damage state of the structure using the results of these measurements and corresponding numerical analyses. An attempt was also made to assess the applicability of traditional displacement-based vulnerability estimation methods in the health monitoring of structures under vibrations with a character different from those due to seismic excitations.

Effect of alkaline-earth oxides on firing behaviour of monoporosa wall tile bodies

Özgür Cengiz,Alpagut Kara 한양대학교 세라믹연구소 2018 Journal of Ceramic Processing Research Vol.19 No.3

For the production of ceramic wall tiles, effective sintering has become increasingly important in recent years to reduce firingtimes and/or peak firing temperatures and thus cope with high energy costs and environmental issues. This study was aimedto investigate the effects of alkaline-earth oxides on the fast-firing behaviour of wall tile bodies. To this end, several bodyformulations with different amounts of calcite and magnesite were prepared and fast fired under laboratory conditions. Thesintering behaviour of the representative formulations was evaluated using a double-beam non-contact optical dilatometer(ODHT). Thermal properties were characterised by TG-DTA. Phase and microstructural analyses were performed by XRDand SEM, respectively. The results showed that an optimum combination of the aforementioned earth alkalines has aconsiderable influence on lowering the peak firing temperature, shortening the firing cycle and improving the glaze qualityby lowering the decomposition temperature of carbonates in the formulations.

Structural repairing of damaged reinforced concrete beam- column assemblies with CFRPs

Özgür Yurdakul,Özgür Avşar 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.3

Depending on the damage type as well as the level of damage observed after the earthquake, certain measures should be taken for the damaged buildings. In this study, structural repairing of two different types of damaged RC beam-column assembly by carbon fiber-reinforced polymer sheets is investigated in detail as a member repairing technique. Two types of 1:1 scale test specimens, which represent the exterior RC beam-column connection taken from inflection points of the frame, are utilized. The first specimen is designed according to the current Turkish Earthquake Code, whereas the second one represents a deficient RC beam-column assembly. Both of the specimens were subjected to cyclic quasistatic loading in the laboratory and different levels of structural damage were observed. The first specimen displayed a ductile response with the damage concentrated in the beam. However, in the second specimen, the beam-column joint was severely damaged while the rest of the members did not attain their capacities. Depending on the damage type of the specimens, the damaged members were repaired by CFRP wrapping with different configurations. After testing the repaired specimens, it is found that former capacities of the damaged members were mostly recovered by the application of CFRPs on the damaged members.